%I #5 Jun 09 2017 19:39:44
%S 0,0,0,1,0,0,0,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0,0,
%T 0,0,0,0,1,0,0,0,1,0,0,0,0,0,0,1,0,0,0,1,0,0,0,1,0,0,0,0,0,1,0,0,0,1,
%U 0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,1,0
%N Fixed point of the mapping 00->0001, 1->00, starting with 00.
%H Clark Kimberling, <a href="/A288314/b288314.txt">Table of n, a(n) for n = 1..10000</a>
%e Iterates, starting with 00:
%e 00
%e 0001
%e 0001000
%e 000100000010
%e 0001000000100010001000
%e 0001000000100010001000001000000100000010
%t s = {0, 0}; w[0] = StringJoin[Map[ToString, s]];
%t w[n_] := StringReplace[w[n - 1], {"00" -> "0001", "1" -> "00"}]
%t Table[w[n], {n, 0, 8}]
%t st = ToCharacterCode[w[11]] - 48 (* A288314 *)
%t Flatten[Position[st, 0]] (* A288315 *)
%t Flatten[Position[st, 1]] (* A288316 *)
%t Table[StringLength[w[n]], {n, 1, 35}] (* A288317 conjectured *)
%Y Cf. A288315, A288316, A288317.
%K nonn,easy
%O 1
%A _Clark Kimberling_, Jun 09 2017